A pathologist determined his cause of death to be from coma, pneumonia and subdural hemorrhaging caused by blunt force trauma, but investigators say those were not the baby's only injuries.

"During the investigation, it was revealed that this young child had suffered a number of injuries," said Berks County District Attorney John Adams.

Pathologists found the baby boy had suffered brain injuries, had three fractured ribs, a left wrist fracture and a fracture on his right shin area, all dating back to the weeks before his death.

But prosecutors ran into some hurdles when it came to charging Jimenez, so they called on the help of a grand jury.

"The grand jury enabled us to compel the testimony of a number of witnesses, and we were able to learn that all of these injuries that took place, took place while in the care and custody of the father of the child," said Adams.

What is so heartbreaking about this story, Adams said, is that Jimenez abused a helpless child.

"That child can not tell us what is wrong. That child, most times, can not even point to the area that hurts. The only reaction that the child can make is to cry," said Adams.

Jimenez was charged with first and third degree murder, aggravated assault, endangering the welfare of children and simple assault. He is being held without bail in the Berks County Jail.

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